Over time, fuel, such as ultra-low sulfur diesel (ULSD), bio-blended diesel and jet fuel, that is stored in tanks becomes contaminated with water and sludge. The presence of these contaminants significantly decreases the lifespan of the storage tank and the parts of the machine/engine in which the contaminated fuel comes into contact. Diesel engines often employ injection systems, spool valves and lift pumps that may be damaged by fuel contaminants and emulsified water.
In most cases, fuel filters are placed between the storage tank and the machine/engine, with the contaminated fuel being filtered while the machine/engine is running. Depending on how long the fuel has been in the storage tank, the fuel can be significantly contaminated. As such, the filter material can be quickly clogged causing the machine/engine to stop or allowing the contaminated fuel to enter the machine/engine. Therefore, filters need to be replaced frequently to avoid damage to the engine/machine. Moreover, current filters are inefficient at removing all water from the fuel before it reaches the machine/engine.
Although some protection is provided to the machine/engine using existing filter systems, the location of the filter does not prevent damage to the storage tank or the removal of contaminants from the storage tank. Excess water (free and emulsified) in the storage tank can cause premature corrosion to the tank, fuel decay and formation of microbial growth, all possibly leading to fuel leaks and formation of acetic acid (via hydrated esters). There is an unmet need for filter system capable of removing all water and contaminants from fuel in a storage tank that prevents these current issues.
Filters and systems for separating contaminants from a fluid are known in the prior art. For example, PCT Application No. WO 2008/046707 to Girondi, and US Patent Application No. 2010/0219116 to Milum teach fluid filter assemblies for the treatment of diesel/oil/fuel.
Girondi describes a fuel filter comprising a casing with an inlet for untreated fuel and an outlet for treated fuel, and internally containing a filtering wall for contaminant removal and a retaining wall holding for back water through coalescence. The retaining wall is downstream of the filtering wall according to fuel flow, and located above the filtering wall within the filter container. Girondi does not teach a system for treatment of fuel stored in a storage tank or a system operating independently of the engine/machine supplied by the storage tank. Milum also describes a fluid filter element and assembly to separate contaminants from a fluid. However, like Girondi's system, Milum's system is not for treatment of fuel in a storage tank that may operate independently of the engine/machine supplied by the storage tank.